This invention relates generally to machines for severing standing crops from the ground using a plurality of rotatable discs having knives mounted thereon to sever standing crop by an impact action upon rotation of the discs and, more particularly, to an improved connector for attaching disc cutter knives to the machine that allows the knives to be easily removed from the rotatable discs and replaced.
Rotary disc cutterbars are well known in the agricultural arts and used in the harvest of a variety of standing crops. A typical disc cutterbar comprises a plurality of cutterheads spaced along the length of the cutterbar. The cutterheads each typically comprise a rotating cutting disc including diametrically opposed cutting blades (though configurations with three or more blades are known) driven by a drivetrain housed within the cutterbar that receives motive power from the prime mover to which the disc mower is attached. For background information on the structure and operation of some typical disc cutterbars, reference is made to U.S. Pat. No. 5,996,323, issued to Campbell, the descriptive portions thereof being incorporated herein in full by reference.
Cutterbars frequently impact rocks and other obstructions in a field which can damage the knives. Further, knives also become dulled by their interaction with the crop and require periodic removal for sharpening or replacement. Knife retention is traditionally accomplished through the use of threaded fasteners which require multiple components and involve time-consuming processes to remove and replace damaged or worn knives. Quick-change knife attachment systems are known wherein the knife is retained on a post-like retainer with a flange and prevented from disengagement by a spring overlapping a portion of the flange. Such arrangements require assembly of the parts in a precise orientation to assure that the knife retainer functions as intended. Prior designs, such as that disclosed in Applicant's pending application Ser. No. 13/667,887 filed on Nov. 2, 2012, could be assembled in multiple orientations which resulted in additional time during assembly to disassemble and reassemble in the correct orientation.
It would be advantageous to provide a locking mechanism for a quick-change knife attachment system that would highlight incorrectly oriented components during cutterhead assembly or wear part replacement to prevent incorrect assembly of the knife retainers. Additional advantages would be realized by a knife retainer system that did not increase the part count for the knife connection. Still further advantages would be realized by a quick-change knife attachment system that permits tool-free knife changes on a rotary cutterhead used on agricultural harvesting machines.